Telephone call-diverter system

Abstract

A telephone call-diverter system for interconnecting an incoming telephone line to an outgoing telephone line so that an incoming telephone call can be transferred to a predetermined remote telephone station. A DC conducting channel is established between the call-diverter system and the incoming telephone line subsequent to the detection of the incoming telephone call, the transmission of dialing signals from the call-diverter system over the outgoing telephone line and a remote station answer condition provided on the outgoing telephone line. In one embodiment, a voice frequency transmission channel is provided in the incoming telephone line connection so that voice frequency communication between the incoming and outgoing telephone lines is provided independent of the completion of the DC connection. Hence, voice frequency signals can be communicated even before the DC connection is established.

What is claimed is: 
     
       1. In a telephone call-diverter system for interconnecting an incoming telephone line to an outgoing telephone line so that an incoming telephone call can be transferred to a predetermined remote telephone station, apparatus for connecting said incoming and outgoing telephone lines to permit voice frequency communication therebetween, comprising: first switch means responsive to a detected ringing signal for completing a circuit from said call-diverter system to said outgoing line, said first switch means further enabling an energizing voltage to be supplied to a power supply terminal;   dial control means for transmitting predetermined dialing signals to said outgoing line from said call-diverter system;   second switch means responsive to the completion of the transmission of dialing signals to supply said energizing voltage to first and second time delay means to thereby energize said first and second time delay means, said first and second time delay means having different time delay characteristics such that said first time delay means generates a first actuating signal prior in time to a second actuating signal generated by said second time delay means;   third switch means actuated in response to said first actuating signal for de-energizing said second time delay means to prevent said second actuating signal from being generated;   answer signal detecting means for detecting an answer signal returned automatically to said call-diverter system over said outgoing line when said predetermined remote telephone station responds to said dialing signals transmitted thereto to thereby deactuate said third switch means and enable said second time delay means to generate said second actuating signal; and   fourth switch means responsive to said second actuating signal for completing a circuit from said incoming line to said call-diverter system to thereby provide a communication channel between said incoming and outgoing lines.   
     
     
       2. The apparatus of claim 1 further comprising voice frequency transmission means connected in shunt relation to said fourth switch means for transmitting voice frequency signals therethrough between said incoming and outgoing lines independent of the completion of said circuit by said fourth switch means. 
     
     
       3. The apparatus of claim 2 wherein said voice frequency transmission means include capacitor means connected in a circuit parallel to said fourth switch means. 
     
     
       4. The appratus of claim 1 further comprising timing means having a predetermined time constant for producing a disconnect signal within a predetermined time after said first switch means responds to said ringing signal; said timing means being connected to said first switch means to supply said disconnect signal thereto to thereby interrupt said completed circuit from said call-diverter system to said outgoing line. 
     
     
       5. The apparatus of claim 4 wherein said timing means comprises an R-C network coupled to said power supply terminal and supplied with said energizing voltage; and fifth switch means actuated when said R-C network is electrically charged to a predetermined level for supplying said disconnect signal to said first switch means. 
     
     
       6. The apparatus of claim 1 wherein said answer signal detecting means comprises sixth switch means for supplying an energizing voltage to said third switch means; and means responsive to a predetermined answer signal applied to said outgoing line for controlling said sixth switch means to interrupt the supply of said energizing voltage from said third switch means. 
     
     
       7. The apparatus of claim 6 wherein said first and second time delay means comprise first and second charging circuits, respectively; said first charging circuit having a faster charging time than said second charging circuit and being coupled to said third switch means for supplying said first actuating signal thereto when electrically charged to a predetermined level; said second charging circuit being coupled to said third switch means and being inhibited thereby from reaching a predetermined charge level when said third switch means is actuated and supplied with said energizing voltage. 
     
     
       8. In a telephone call-diverter system wherein dialing signals are transmitted via an outgoing telephone line to establish a communication channel to a predetermined remote telephone station in response to an incoming telephone call received over an incoming telephone line, apparatus for establishing a DC connection to said incoming telephone line, comprising: first time delay means actuated in response to the completion of transmission of dialing signals for generating a connect energizing signal after a first time delay;   second time delay means actuated in response to the completion of transmission of dialing signals for generating an inhibit energizing signal after a second time delay, said first delay being greater than said second time delay;   connecting switch means responsive to said connect energizing signal for connecting said incoming telephone line to said telephone call-diverter system via a DC conduction path;   inhibit switch means connected to said first time delay means and responsive to said inhibit energizing signal for inhibiting said first time delay means from generating said connect energizing signal; and   disabling means for disabling said inhibit switch means when a predetermined condition of said outtgoing telephone line is sensed, to thereby permit said first time delay means to generate said connect energizing signal.   
     
     
       9. The apparatus of claim 8 wherein each of said first and second time delay means comprises a charging circuit actuated to be charged to a predetermined level, whereby the respective energizing signals are generated when said respective predetermined levels are attained. 
     
     
       10. The apparatus of claim 9 wherein said inhibit switch means comprises actuable clamp means coupled to said first charging circuit for clamping the charge level of said first charging circuit to a value less than said predetermined level. 
     
     
       11. The apparatus of claim 10 wherein said clamp means comprises controlled rectifier means for connecting said first charging circuit to a reference potential and having a control input terminal coupled to said second charging circuit to receive said inhibit energizing signal therefrom. 
     
     
       12. The apparatus of claim 11 wherein said disabling means comprises means for selectively supplying an operating potential to said controlled rectifier means such that said operating potential is interrupted when said predetermined condition of said outgoing telephone line is sensed.